Tunneling methods and apparatus

ABSTRACT

A tunnel is constructed by driving two parallel side channels and then an arched channel interconnecting the parallel channels, forming a roof lining in the arched channel, and excavating the ground material lying beneath the roof lining.

United States Patent Arsuaga Nov. 4, 1975 [54] TUNNELING NIETHODS AND APPARATUS 1,242,217 10/1917 McAlpine 61/42 2,055,876 9/1936 Newman.....

[75] Inventor: Javer Al'suaga d spam 3,616,650 11/1971 Eber et a1. 61/42 [73] Assignee: Gewerkschaft Eisenhutte Westfalia,

Wethmar near Lunen, Germany Primary Examiner'Paul R. Gilliam [22] Flled: 1974 Assistant Examin'erDavid H. Corbin [21] APPL No 453,474 Attorney, Agent, or Firm-Sughrue, Rothwell, Mion,

Zinn & Macpeak [30] Foreign Application Priority Data Mar. 27, 1973 Spain 414134 [57] ABSTRACT [52] US. Cl 61/42; 61/63 [51] Int. Cl. E21D 9/08 A tunnel is constructed by driving two parallel Side Field of Search 45 channels and then an arched channel interconnecting 299/11 the parallel channels, forming a roof lining in the arched channel, and excavating the ground material [56] References Cited lying beneath the roof lining.

UNITED STATES PATENTS 960,940 6/1910 Jackson 61/42 3 Claims, 14 Drawing Figures US. Patent Nov. 4, 1975 Sheet 2 of4 Sheet 3 of 4 3,916,630

US. Patent Nov. 4, 1975 U.S. Pater itg NoY.4, 1975 Sheet4 of4 3,916,630

TUNNELING METHODS AND APPARATUS BACKGROUND OF INVENTION In conventional tunneling methods, the rock or earth through which the tunnel is to be cut is removed by a tunneling machine which may incorporate a shield having sharp ended elements or a rotary cutting drum, or other device. The cavity which is produced is then lined with, for example, concrete cast in situ, to form an arch to support the tunnel roof. Support for the roof lining may be provided by beams constructed in channels running along side the main tunnel. As a general rule, temporary supports must be provided to prevent the collapse of the natural roof before the roof lining is ready to take the load by itself, this precaution being particularly necessary when the natural roof of the tunnel has little or no tendency to be self supporting.

These problems become more pronounced with the increase in diameter of the tunnel being driven.

SUMMARY OF THE INVENTION The object of the present invention is to overcome these problems by utilising the undisturbed rock or earth through which the tunnel is to be driven to support the roof lining until the same is capable of supporting the natural roof. Accordingly, a slot-like channel is driven along the line of the intended roof lining. When a sufficient length of this channel has been formed, the roof lining is constructed in it by, for example, casting concrete in-situ therein. During the time that the roof lining is being formed, it is supported by the core of rock which lies beneath it and which is subsequently excavated to form the tunnel proper. The operation may be commenced by driving two parallel channels along lines which coincide with the lateral edges of the roof lining. These may then be reinforced with concrete and serve as temporary roadways from which the slot-like channel is driven. When this procedure is adopted, the slot-like channel may be driven using a retreat method of working, that is to say, commencing at the far ends of the parallel channels (or at some intermediate position along their lengths) and then working backwards towards the starting point. While the slotlike channel is being formed in this way, the driving of the parallel channels may continue in the advance direction. When the slot-like channel has been driven all the way back to the starting point, has been lined, and the lining is ready to support the weight of the natural roof, the rock under the roof lining may be excavated and the floor lining introduced. At the same time, the sections of the parallel channels alongside the completed roof lining may be premanently filled with concrete or other premanent reinforcement. At a distance ahead of the first slot-like channel to be formed, a second such channel may be commenced and is continued in the retreat direction until it reaches the end of the first section of roof lining. Tunneling proceeds progressively in this manner. Alternatively, the side and slotlike channels may be driven together in the advance direction, the main excavating machine following behind at a suitable distance.

As a further alternative the side channels may be cut first and the slot-like channel next, but all in the advance direction.

The equipment for cutting the slot-like channel may be carried into position along the parallel side channels, and the material removed may be conveyed away 2 from the site of working along one or both of these channels.

Any suitable tunneling machine may be used to drive the parallel side channels, and may be in the form of a tunneling shield consisting of an array of sharp-ended planks, some of which are anchored in place while others are thrust forward, each of the planks alternately being moved and then anchored. Altemately, the side channels may be driven by a tunneling machine having a rotary cutter head or drum or chain cutter, such machines being well known in the art.

For driving the slot-like channel in which the roof lining is to be formed, I prefer to use a novel apparatus which comprises a frame unit assembled from a number of articulated sections. As a general rule, the roof lining will have an arched configuration although this may not always be the case and the frame unit is profiled accordingly. Supported on the upper side of the frame unit is an array of sharp ended tunneling shield elements some of which are forced forwards against the reaction of others which are anchored in place, whereafter the previously anchored elements are advanced andthe remaining ones held stationary. These shield elements cut out the upper or outer extremity of the slot-like channel. Below these shield elements, the lower extremity of the channel is removed by a cutter which is traversed through the channel throughout all or part of the length thereof. This cutter may be in the form of a planer tool which is equipped with cutting his and is reciprocated by an endless traction element. Alternatively, the cutter may be in the form of a continuously rotating cutter chain trained along the length of the channel, or a shearing type cutter which is traversed back and forth through the channel and is equipped with rotary cutters. The cutter may be used to convey the material removed from the rock face into the side channels. Alternatively, the cutter may load the material onto a conveyor of the endlessband or scraperchain type which conveys it to the side channels or, if-the' slope of the arch is sufficient, onto a chute along which the material slides under the effect of gravity. Within the side channels the material may be removed along f suitable conveyors, together with the material being removed by the machines driving these channels. f

The cutter and conveyor or chute supported by the frame unit may be mounted on skids which travel across the core of rock remaining under the slot-like channel. These skids are not required to have any ground breaking action and therefore may be spaced apart by a distance greater than that between the shield elements.

The frame unit is composed of sections articulated to one another by joints provided either between the upper or the lower struts of adjacent frame units. Pivotal adjustment between adjacent frame sections may be obtained by fluid operated rams. One component (either piston or cylinder) of such a ram is mounted fast to one component while the other is loosely engaged with the adjacent frame section so that the latter, upon being displaced during extension of the ram, rotates relative to the extending ram component. To achieve this effect the extending ram component usually the piston rod may be provided with a wedge shaped head which enters a wedge shaped recess in the adjacent frame section, or with a convex head entering a concave recess. Yet again, the head and recess may be part-spherical.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cross-sectional view of a tunnel being driven in accordance with the invention,

FIGS. 1A to ID are diagrammatic perspective views showing the procedure steps used in driving a tunnel in accordance with the invention,

FIG. 1E shows an alternate procedure,

FIG. 2 is a view looking in the same direction as FIG. 1 showing to a larger scale two sections of the support frame unit,

FIG. 3 is a section taken on the line A-B in FIG. 1,

FIG. 4 is a plan view showing the detail of FIG. 3.

FIG. 5 shows an alternative embodiment of the rams used in FIG. 2, to a larger scale,

FIG. 6 shows a further alternative embodiment of the rams used in FIG. 2, to a larger scale,

FIG. 7 shows an alternative embodiment of the atticulated joint between frame sections, and

FIGS. 8 and 9 show two alternative designs which may be applied to the cutting shield elements, or, if inverted, the skids.

DESCRIPTION OF PREFERRED EMBODIMENTS The Tunneling Method An essential feature of my novel tunneling method is that the core of ground material which lies within the main tunnel section supports the roof lining until the latter is ready to bear the weight of the ground material above the tunnel.

This principle may be carried into effect in several ways. In the first method, namely that depicted in FIGS. 1A to 1D, two parallel side channels 2,2 are driven at positions which coincide with the side walls of the final tunnel. In due course, these channels will contain beams which will provide end support for the roof arch of the tunnel. These side channels may be driven by any conventional tunneling machines 102 having a rotary cutter, or a tunneling shield made up from sharp ended planks interconnected in two groups, one group advancing against the reaction of the others which remain stationary anchored against the wall of the channel. When a suitable length of channels 2,2 has been driven, they are reinforced and interconnected by an arched channel 2" (FIG. 1B) in which is assembled tunneling apparatus 103 in accordance with the invention and to be described later. This progresses in the retreat direction, excavating an arched, slot-like channel or hollow delimited on its upper side by a natural or green roof of rock 9 and on its lower side by a floor 10 on the surface of the core 3. This space is filled behind the apparatus with concrete to form a roof lining 40, or the lining constructed in another way. While the concrete is setting, or the lining being assembled, it is supported by the humped core of rock 3 beneath it (FIG. 1C). The material which is removed by the apparatus 103 is conveyed, or slides down chutes, into either or both of the channels 2,2 through which it is transported on conveyors of the belt or scraper chain type, for example, and as depicted by arrow 104. Simultaneously with the formation of the slot-like channel and the roof lining therein, the channels 2,2 are being extended, ready for the construction of a further channel (FIG. 2D), when the apparatus 103 is removed from the first channel. Tunneling then proceeds indefinitely in this wise.

Following completion of the roof lining 40, one or more high speed wide face tunneling machines 105 is employed to work under the finished roof to remove the full tunnel cross-section. The floor lining 4 may be introduced and the side channels, already reinforced to I bear the roof lining 40, may be closed off if desired.

In a second method depicted in FIG. 1 and FIG. 1E,

the work of forming the side channels 2,2 and the slotlike channel proceeds together in the advancing direction 30. The combined system of channels is then filled with concrete or other lining but leaving passageways 2" along the lining of the channels 2,2 for access and the removal of material along a conveyor. At a position rearwardly of the apparatus 103 follows the machine 104, removing the fullface in the safety of the finished roof lining.

The Tunneling Apparatus The apparatus 103 rests on the core of rock 3 in both embodiments and is shown in greater detail in FIGS. 1 and 2 onwards.

The apparatus comprises a frame unit assembled from sections 6, 7, 8 each in the form of a framework having upper and lower beams interconnted by struts. The sections are interconnected to form an archshaped structure above which is carried an array of sharp fronted tunneling shield elements or boards 13 best depicted in FIG. 3. These elements are arranged in groups, each group being held stationary while another is advanced as well known in the art. The elements 13 cut away the upper side of the channel to form the natural roof 9. The lower part of the slot-like channel down to floor 10 is removed by a device 11 which as illustrated takes the form of a planer provided with cutting picks or shear faces 15 (FIG.4) which is guided on a conveyor 12. The material cut down by the planer falls on to the conveyor and is conveyed therealong by moving flights to the right hand end (FIG.1) where it falls onto the conveyor, extending through channel 2. Alternatively, the conveyor is unpowered and the material slides under gravity into both of channels 2,2.

Yet again, the material may be carried along by the shear faces 15 of the planer itself.

The planer is supported and guided on the conveyor 12 which is urged forwards by a ram shown in FIG. 3. This equipment is all supported on the underside of the frame. Naturally, these skids have no cutting function and they are positioned at substantial distances apart compared with elements 13 see FIG. 1.

The various frame sections are articulated together at 20 on the lower side of the unit. One possible joint is shown in more detail in FIG. 7 and consists of two tubes 22,22 mounted at a certain fixed distance apart on a spacer plate 24. The tubes 22 are embraced by complementary channeled sections 23,23 on adjacent frame sections so as to leave a gap between the facing sides of these sections. The interior tapering of the sections 23,23 towards their mouths retains the sections in contact with the assembly 22,22, 24, the sections being able to swing relative to each other.

The embodiment of the joint shown in FIG. 2 differs somewhat from that shown in FIG. 7, the sections being equipped with oppositely directed tongues which slot loosely into facing grooves defined by inverted L-sectioned bars carried by plate 24.

The sections may be pivoted about the joint 20 by rams 21. As shown in FIG. 2, section 6, for instance, carries the cylinder of a ram which has a wedge shaped head fitting within a complementary cavity 26 in the section 7. In the alternative construction shown in FIG. 6, the head 25 is convex and fits into a complementary concave recess 26'. Both of these embodiments are capable only of counteracting compressive forces applied to the overall structure. In the version shown in FIG. 5, however, the head 25' is retained within an almost closed channel 26' so that tensile and compression forces may be counteracted. Means are provided between the sections to detect the forces acting on the structure and the rams may be actuated accordingly.

During the advance of the apparatus, the shield elements and skids must be periodically anchored in place to provide a reaction against which selected other shield elements and planer 11 may be pressed forward. As shown in FIG. 8, this reaction may be provided by sprags 27 which can be forced outwards into the natural roof by a rack and pinion gearing 29 at an oblique angle to the direction of advance 30. The gearing is operated from a lever which may be displaced by a ram, or alternatively the sprags may be carried by the piston rods of rams. In the modification shown 'in FIG. 9, the sprags 27' are provided at the ends of the shield elements, parallel to the oblique cutting edge 28 of the latter. Projection of the sprags takes place parallel to this edge. The end faces of this type may be formed as replaceable wear parts which serve both to anchor the selected shield elements and to guide the apparatus as a whole, this feature being of particular value because of the different techniques being employed. The skids may be similarly equipped.

In operation of the apparatus forces are developed at the upper part 18 of the apparatus which act in different directions to those in the lower part 19, because of the different removal techniques being practised. These forces may result in sufficient friction being developed to render unnecessary the use of anchoring sprags.

What I claim is:

1. A method of driving underground tunnels having an arched roof profile, comprising the steps of:

a. driving two parallel channels, one at each side of the intended tunnelprofile,

b. forming an arched channel interconnecting the two parallel channels,

c. assembling in the arched channel a framework comprising a plurality of interconnected sections, said framework resting upon skids and being covered by sharp ended shield elements, an arched conveyor being supported on said skids and extending between the two parallel channels,

d. advancing selected groups of the shield elements alternately, to cut away the upper side of an arcuate channel and form a natural roof,

e. reciprocating a planer back and forth along the conveyor between the two parallel channels to remove material from beneath the shield elements, the material removed being conveyed along the conveyor to at least one of the parallel channels,

f. monitoring the stresses in the framework sections,

g. applying counteracting forces between the sections in response to the monitoring, whereby the arched channel is extended, and

h. filling the extended arched channel with a lining material.

2. A method as claimed in claim 1, wherein the parallel channels are reinforced by concreting before the arched channel is formed and extended, and the lining is formed by filling the arched channel with concrete.

3. A method as claimed in claim 1, wherein the parallel channels are driven in the advance direction for at least part of the length of the intended tunnel, the arched channel is driven by retreat working, and the material is removed from beneath the roof by working in the advance direction. 

1. A method of driving underground tunnels having an arched roof profile, comprising the steps of: a. driving two parallel channels, one at each side of the intended tunnel profile, b. forming an arched channel interconnecting the two parallel channels, c. assembling in the arched channel a framework comprising a plurality of interconnected sections, said framework resting upon skids and being covered by sharp ended shield elements, an arched conveyor being supported on said skids and extending between the two parallel channels, d. advancing selected groups of the shield elements alternately, to cut away the upper side of an arcuate channel and form a natural roof, e. reciprocating a planer back and forth along the conveyor between the two parallel channels to remove material from beneath the shield elements, the material removed being conveyed along the conveyor to at least one of the parallel channels, f. monitoring the stresses in the framework sections, g. applying counteracting forces between the sections in response to the monitoring, whereby the arched channel is extended, and h. filling the extended arched channel with a lining material.
 2. A method as claimed in claim 1, wherein the parallel channels are reinforced by concreting before the arched channel is formed and extended, and the lining is formed by filling the arched channel with concrete.
 3. A method as claimed in claim 1, wherein the parallel channels are driven in the advance direction for at least part of the length of the intended tunnel, the arched channel is driven by retreat working, and the material is removed from beneath the roof by working in the advance direction. 